Method and device for transmitting and receiving channel state information in wireless communication system

Abstract

The present invention relates to a wireless communication system. A method by which a user equipment reports a channel state information (CSI) in a wireless communication system, according to one embodiment of the present invention, can comprise the steps of: setting up a first CSI process in which a subframe pattern for a first subframe set, which uses an almost blank subframe (ABS), and a second subframe set, which does not use the ABS, is set; setting up a second CSI process in which the subframe pattern is not set; setting a second rank indicator (RI) of the second CSI process to be the same as a first RI corresponding to the second subframe set when the second CSI process is established so as to have the same RI as the first CSI process; and transmitting the CSI on the basis of the first CSI process and/or the second CSI process.

The invention claimed is: 
     
       1. A method of reporting channel state information (CSI) in a wireless communication system, the method performed by a user equipment and comprising:
 configuring a first CSI process, in which subframe patterns for a first subframe set based on an almost blank subframe (ABS) and a second subframe set which is not based on the ABS are configured; 
 configuring a second CSI process in which the subframe patterns are not configured; 
 configuring a second rank indicator (RI) of the second CSI process to be the same as a first RI corresponding to the second subframe set when the second CSI process is configured to have the same RI as that of the first CSI process; and 
 transmitting the CSI on the basis of at least one of the first CSI process and the second CSI process. 
 
     
     
       2. The method of  claim 1 , wherein, if the first CSI process and the second CSI process are configured to periodically report the CSI, the second RI is set to the same value as that of the first RI which is reported most recently before the second RI is reported. 
     
     
       3. The method of  claim 2 , wherein a second precoding matrix indicator (PMI) of the second CSI process is set to the same value as that of a first PMI which is reported most recently before the second PMI is reported. 
     
     
       4. The method of  claim 2 , wherein a second channel quality indicator (CQI) of the second CSI process is set to the same value as that of a first CQI which is reported most recently before the second CQI is reported. 
     
     
       5. The method of  claim 1 , wherein, if the first CSI process and the second CSI process are configured to aperiodically report the CSI, and if the first CSI process and the second CSI process are requested to be CSI reported at the same time, the second RI is set to the same value as that of the first RI corresponding to the second subframe set. 
     
     
       6. The method of  claim 5 , wherein the second PMI and second CQI of the second CSI process are set to the same values as those of the first CSI process, which are reported at the same time. 
     
     
       7. A method of reporting channel state information (CSI) in a wireless communication system, the method performed by a user equipment and comprising:
 configuring a first CSI process in which subframe patterns for a first subframe set based on an almost blank subframe (ABS) and a second subframe set which is not based on the ABS are configured; 
 configuring a second CSI process in which the subframe patterns are not configured; 
 configuring a first rank indicator (RI) corresponding to the second subframe set to be the same as a second RI of the second CSI process when the first CSI process and the second CSI process are configured to have the same RI as each other; and 
 transmitting the CSI on the basis of at least one of the first CSI process and the second CSI process. 
 
     
     
       8. The method of  claim 7 , wherein, if the first CSI process and the second CSI process are configured to periodically report the CSI, the first RI is set to the same value as that of the second RI which is reported most recently before the first RI is reported. 
     
     
       9. The method of  claim 8 , wherein a first precoding matrix indicator (PMI) corresponding to the second subframe set is set to the same value as that of a second PMI which is reported most recently before the first PMI is reported. 
     
     
       10. The method of  claim 8 , wherein a first channel quality indicator (CQI) corresponding to the second subframe set is set to the same value as that of a second CQI which is reported most recently before the first CQI is reported. 
     
     
       11. The method of  claim 7 , wherein, if the first CSI process and the second CSI process are configured to aperiodically report the CSI, and if the first CSI process and the second CSI process are requested to be CSI reported at the same time, the first RI is set to the same value as that of the second RI of the second CSI process. 
     
     
       12. The method of  claim 11 , wherein the first PMI and the first CQI, which correspond to the second subframe set, are set to the same values as those of the second CSI process, which are reported at the same time. 
     
     
       13. A user equipment for reporting channel state information (CSI) in a wireless communication system, the user equipment comprising:
 a radio frequency (RF) unit that transmits radio signals; and 
 a processor, connected with the RF unit, that: 
 configures a first CSI process in which subframe patterns for a first subframe set based on an almost blank subframe (ABS) and a second subframe set which is not based on the ABS are configured, 
 configures a second CSI process in which the subframe patterns are not configured, 
 configures a second rank indicator (RI) of the second CSI process to be the same as a first RI corresponding to the second subframe set when the second CSI process is configured to have the same RI as that of the first CSI process, and 
 controls the RF unit to transmit the CSI on the basis of at least one of the first CSI process and the second CSI process. 
 
     
     
       14. A user equipment for reporting channel state information (CSI) in a wireless communication system, the user equipment comprising:
 a radio frequency (RF) unit that transmits radio signals; and 
 a processor, connected with the RF unit, that: 
 configures a first CSI process in which subframe patterns for a first subframe set based on an almost blank subframe (ABS) and a second subframe set which is not based on the ABS are configured, 
 configures a second CSI process in which the subframe patterns are not configured, 
 configures a first rank indicator (RI) corresponding to the second subframe set to be the same as a second RI of the second CSI process when the first CSI process and the second CSI process are configured to have the same RI as each other, and 
 controls the RF unit to transmit the CSI on the basis of at least one of the first CSI process and the second CSI process.